High power, Full-band UHF TV Broadcast Amplifiers
Two new UHF TV amplifiers, one designed specifically for digital service, the other designed for analog service, both with the highest power density currently available, are now offered from Power Module Technology (PMT). The advanced technology incorporated into these amplifiers is also available for microwave applications such as radar, avionics and digital communications. These solid-state pallet amplifiers outperform tube technology providing economies of scale superior to others offered in the market today. Operating cost may be reduced by as much as 30 percent using these new solid-state amplifiers, while providing many years of uninterrupted service.
Power Module Technology has introduced the PP470-860-1000 pallet using LDMOS field effect transistors (FET) provided by NXP. It is designed to deliver the highest RF output power, efficiency and gain available anywhere. Exceptionally rugged, these devices are ideal for use in PMT’s broadcast amplifiers providing MTTF/MTBF beyond other products offered in the market today. The PP470-860-1000 is a high power linear Class AB pallet amplifier featuring the latest generation laterally diffused metal oxide semiconductor (LDMOS) transistors, covering the entire UHF TV band. The PP470-860-1000 has 250 W of DVB-T Average Digital Output Power, with shoulder IMDs of less than -33 dBc. Figure 1 shows the gain and efficiency over the operating frequency band (470 to 860 MHz).
Figure 1 PP470-860-1000 gain and efficiency over operating frequency.
- 250 W Digital Average Power
- 1000 W Peak Digital Power
- Latest generation LDMOS transistors
- Channel 14-69: 470 to 860 MHz
- 50 ohms input/output
- Thermal tracking bias
- No circuit tuning or RF assembly
A new standard in analog UHF television amplifiers, the PP470-860-600 (see Figure 2) is a high power, full-band (channels 14-69) amplifier designed for analog operation with 600 W of Peak-Sync power across the entire UHF TV band, 470 to 860 MHz. Use of NXP’s latest generation LDMOS power transistors is key in providing high performance. High efficiency cooling is obtained though the use of a nickel plated copper baseplate and overall amplifier efficiency is typically 40 percent at 600 W Peak-Sync power. Requiring a supply voltage of 40 VDC, a cost-effective telecomm switching power supply can be used, providing high efficiency and high reliability.
Figure 2 Photo of PP470-860-600.
The PP470-860-600 can also be used in digital applications supplying 150 W digital average power DVT-B (8K OFDM). Four can be combined for a nominal 500 W of average digital power, or using a back-to-back heatsink, a nominal 1000 W of average digital power.
No circuit tuning is required. With the amplifier fully tested at the factory, the customer simply bolts down the amplifier, connects RF and DC power, and is ready to start transmitting. At 3½" wide and 1" high, the amplifier is sized for installation with four across a 19-inch rack for a combined 2000 W of Peak-Sync analog output power. Customers can use a back-to-back heatsink for 4000 W of combined analog power.
Power Module Technology is a leader in high power RF amplifier design. Its FM amplifier lineup includes one of the highest power pallet amplifiers at 1500 W CW, currently the highest power density at over 70 W/in2.
The company’s design expertise is being used to expand high power amplifier frequency coverage into the microwave region for CW and pulsed applications using multiple power transistor technologies. High gain, increased efficiency and improved ruggedness are now available in solid-state amplifiers operating as high as S-band. Custom and semi-custom designs are also available. (All of PMT’s amplifiers come with a two-year warranty on parts and workmanship.)
RS No. 300